Remove migration from post-0.1.0

We had made the migrations from master, but that isn't what edx-platform
was using yet.  This migration is re-made from 0.1.0, which removes
things that happened after 0.1.0.

submissions/migrations/0001_initial.py

@@ -3,7 +3,6 @@ from __future__ import unicode_literals
 
 from django.db import migrations, models
 import jsonfield.fields
-import submissions.models
 import django.utils.timezone
 import django_extensions.db.fields
 
@@ -25,16 +24,6 @@ class Migration(migrations.Migration):
             ],
         ),
         migrations.CreateModel(
-            name='ScoreAnnotation',
-            fields=[
-                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('annotation_type', models.CharField(max_length=255, db_index=True)),
-                ('creator', submissions.models.AnonymizedUserIDField()),
-                ('reason', models.TextField()),
-                ('score', models.ForeignKey(to='submissions.Score')),
-            ],
-        ),
-        migrations.CreateModel(
             name='ScoreSummary',
             fields=[
                 ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
@@ -49,7 +38,7 @@ class Migration(migrations.Migration):
             name='StudentItem',
             fields=[
                 ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
-                ('student_id', submissions.models.AnonymizedUserIDField()),
+                ('student_id', models.CharField(max_length=255, db_index=True)),
                 ('course_id', models.CharField(max_length=255, db_index=True)),
                 ('item_id', models.CharField(max_length=255, db_index=True)),
                 ('item_type', models.CharField(max_length=100)),